It is important to have a sense of artistic materials when exploring color theory. Below are some of the more efficient and economical tools every artist needs. Simply select one of the red dots to further examine a specific tool.
X-Acto Knife

Precision is crucial when constructing exercises in color theory. If edges are not clean and measurements incorrect, optical illusions won't be as strong or will fail to work altogether.
Materials
Gouache
Gouache is a water-based paint that acts like an opaque watercolor. Though it does take a bit getting used to because of its tendency to clot easily, it is ideal when creating color illusions because of the even tones it can produce with a minimal amount of effort. However, allow yourself practice when using gouache, it can be a frustrating medium to work in, but if applied correctly, works beautifully.
Rubber Cement
Rubber cement should always be used when handling colored paper because of its incredible anti-wrinkle property. Moreover, this glue dries faster and lighter than most other adhesives. When creating quick color theory exercises, use rubber cement to avoid messes and longer drying.
X-Acto Knife
A sharp knife is a must for any craftsman who cherishes clean and precise lines. This knife fits easily in one's hand, weighs almost nothing, and cuts sharply through most craft mediums. It can be found at most hardware stores.
Color-Aid
This packet of 314 different colors includes a wide range of variations among hues, tints and shades. This assortment is perfect for the pupil studying color relationships and comes in handy when training the eye to notice color differentiations.
Synthetic Brushes
When handling water-color and gouache paint, it is best to use synthetic sable brushes because they retain paint pigment more than other brushes because they contain deeper ridges along their hair strands. These brushes can be found for cheap and do the job very well.
Palette Knife
The palette knife is vital for any painter, but is especially useful when handling gouache as this paint can be difficult to mix. Because one must crush pigments into one another in order to mix paint, it's perfect to have this lightweight knife.